<?php 
	session_start();
	$captcha = imagecreate(100, 30);
	$bg = imagecolorallocate($captcha, 255, 255, 255);
	$font_color = imagecolorallocate($captcha, 106, 189, 197);
	$font = "font/Lobster.otf";

	$string = md5(microtime() * mktime());
	$text = substr($string,0,7);
	$_SESSION['security_code'] = $text;

	imagettftext($captcha, 20, 0, 5, 25, $font_color, $font, $text);
	header("Content-type: image/png"); 
	imagepng($captcha);
	imagedestroy($captcha);
?>